Phonograph turntable driving mechanism



Feb. l, 1938.l F Q BARTON 2,106,710

PHoNoGRAPH TURNTABLE DRIVING MECHANISM Filed Feb. 13, 1952 IN VEN TOR.

Patented Feb. 1, I 1938 UNTE STATES oFFIClV PHONOGRAPH TURNTABLE DRIVINGMECHANISM tion of Delaware Application February 13, 19,32, Serial No.592,704

15 Claims.

My invention relates to phonograph turntable driving mechanism and, moreparticularly, is an improvement over the invention disclosed in theco-pending application of Benjamin R. Carson,

Serial No. 512,244, filed January 30, 1931, and

assigned to Radio Corporation of America.

In reproducing sound from phonograph records of the disc type, it isnecessary to rotate the disc at a constant, predetermined speed.Heretofore,

l0 the speed of the usual phonograph record was '78 to 80` R. P. M. butthere recently have been lntroduced phonograph disc records whichrequire a speed of approximately 331A; R. P. M. Obviously, if aphonograph is to have commercial merit, it must be so designed thatrecords of either of the aforesaid types may be reproduced thereby, atwill.

In the Carson application, speed changing mechanism of the typeincluding a plurality of gears is disclosed, together with meanswhereby,

through proper manipulation-of an adjusting element, the recordsupporting platen may be caused to rotate at 78 or 331/3 R. P. M.Mechanisms of the Carson type have gone into extensive public use andhave, in general, given a fair degree of satisfaction. It has beennoticed, however, by those who are extremely critical, that the gearteeth in the said Carson mechanism tend to introduce minorirregularities into the rotation of the disc, which irregularities causewows, or, in other words, momentary changes of pitch of the reproducedsounds.

It is, accordingly, an object of my invention to provide a reducing gearfor phonograph mechanism that shall be smoother in action than thereducing gears of the Carson type heretofore known.

It is a further object of my invention to provide mechanism of the typedescribed that shall enable the reproduction of sounds from slowspeedrecords without the introduction of objectionable wows.

It isa further and more specic object of my invention to providemechanism of the type described that shall be devoid of gears.

In accordance'with my invention, I provide a phonograph having a.driving spindle adapted to rotate at 78 R.: P. M., to which is attachedari inner ball race. I further provide an outer ball race which, atwill, may be held stationaryand,

in addition, I provide a ball retaining cage having means aixed theretowhereby motion thereof may be transmitted to a phonograph turntable. Invaddition, I provide a speed controlling device whereby thev outer ballrace may be rei ball retaining cage.

leased, at will, and the inner ball race may be coupled to either theball retaining cage or the loutside race for the purpose of transmittmgmotion to the super-incumbent turntable at '78 R. P. M.

The novel features that I consider characteristic of my invention areset forth with particularity in the appended claims. The inventionitself, however, both as to its organization and its method ofoperation, together with additional 10 objects and advantages thereof,will best be understood from vthe following description of a specificembodiment, when read in connection with the accompanying drawing,wherein the single gure is a view in vertical cross-section of 15phonograph turntable speed changing mechanism comprising a preferredembodiment of my invention.

Referring to the drawing, my improved mechanism comprises a phonographturntable i havidg a, depending boss 3 provided with a transversekeyway, or slot, 5 into which extends a transverse pin l carried by adriven spindle 9. A bearing Il, of any suitable type, may be provided,whereby the weight of the ydriven spindle 25 and the turntable issupported.

'Ihe driven spindle has a ball retaining cage I3 aiixed thereto anddepending therefrom. A plurality of balls l5 are provided which aremaintained in Vspaced relation by the depending 30 An inner ball race Ilis'v ailixed to the upper end of a driving vspindle I9 co-axial with therst referred to spindle 9, the said driving spindle being operativelyconnected to a prime mover, such as a motor M, for rota- 35 tion at 78R. P. M. An outer ball race 2| is provided, to which is affixed adepending element 23.

i The depending element may take the i'orm of an annular flangecompletely encircling the outer ball race and being provided with aplurality of 40 inwardly directed gear teeth, or it may be a singledetent device, as illustrated.

Obviously, if the outer ball race is prevented from rotating, rotarymotion from the inner ball race will be transmitted to the balls in there- 45 tainer l 3, and the said ball retainer will be caused to rotateat a speed determined by the relative diametersv of the balls and theinnerball race. 'In order that the outer ball race may be held againstrotation, I provide a pivoted lever 24, 50 having a attenedend portion25, which, when the lever is raised, moves into engagement with the4depending velement 23 to restrain it from rotating. A supporting device21 may also be pro-1v vided, having a slotted end 29 into which the end55 In the event that it is desired to rotate the turntable at '78 R. P.M., it is, of course, necessary to release the outer ball race and tolock the inner and outer races together, as heretofore explained. Forthis purpose, I provide a collar 3l slidably mounted on the lowerdriving spindle I9 and so dispose another end portion 33 of theaforementioned operatinglever that the collar may be moved axially ofthe said spindle. The collar is provided wtih a pin 35 which extendsoutwardly into the path of the element depending from the outer ballrace. When the lever is depressed to the position shownin the drawing,the outer ball race is released and the pin carried by the collarengages the depending element23 and thus effectively locks the innerspindle to the outer ball race.

Inasmuch as the relative sizes of the several ball races and thediameters of the balls, themselves, may be readily calculated by anyoneskilled in machine design who is provided with the necessary handbooks,it is my opinion that detailed calculations need not be given in orderto render my disclosure complete.

. It will be apparent, from the foregoing disclosure of my improvedphonograph platen driving mechanism that, through its utilization,turntable speeds of either 78 or 331/3 R. P. M. may be had at will. Itshould further be apparent that, inasmuch as all gearing has beenomitted, the turntable, when rotating at, 331/3 R. P. M., will beextremelysteady and its speed will not vary in a manner to introducewows.

Although I have shown and described a specic embodiment of my invention,I am fully aware that many modifications thereof will be readilyapparent to those skilled in the art to which it pertains. My invention,therefore, is not to be restricted except insofar as is necessitated bythe prior art and. by the spirit of the appended claims.

I claim as my invention:

1. In combination, a phonograph record supporting platen, a spindleadapted to be driven at a definite speed, speed changing mechanism ofthe planetary type frictionally geared to the spindle and positionedbetween said spindle and said platen, and means for restraining fromrotating, at will, a portion of said mechanism.

2. In combination, a spindle adapted to be ro- 'tated at avpredetermined speed, planetary gear mechanism comprising a plurality ofball races and a plurality of balls associated therewith carried by saidspindle, a record driving spindle and a ball spacing cage depending fromsaid spindle and adapted to cooperate with the said balls to transmitmotion to said turntable driving spindle.

3. The invention set forth in claim 2 characterized in that means areprovided for, at will, effectively locking said ball races together, toprevent relative motion-therebetween.

4. The invention set forth in claim 2 characterized in that means areprovided whereby-the lower spindle may be, at will, effectively lockedto the outer race.

5; As an article of manufacture. a record platen supporting and drivingspindle provided with a depending ball spacing cage.

6. In combination, a spindle adapted to be driven ata predeterminedspeed, a record platen supporting spindle, motion transmitting means ofthe planetary type jointly carriedlby said spindles, and means for, atwill, locking a portion of said motion transmitting means againstrotation 7. The invention set forth in claim 6 characterized in thatmeans are provided whereby said motion transmitting spindle may beoperatively and immediately connected to a portion of said motiontransmitting mechanism.

8. In combination, a driving spindle, a driven spindle, motiontransmitting mechanism of the planetary type jointly carried by saidspindles, said mechanism comprising an inner ball race carried by thedriving spindle, a ball spacing cage carried by the driven spindle, andan outer ball race disposed in operative relation to said ball spacingcage and said inner race.

9. In combination, a spindle adapted to be driven at a definite speed, aturntable supporting and driving spindle, power transmission means ofthe planetary ball type frictionally geared to said first-named spindle,power take-off means carried by and depending from said turntablespindle and adapted to cooperate with the balls of said transmittingmeans whereby said first and second named spindles are indirectlycoupled together, and means for locking a portion of said transmissionmeans against rotation at -will to cause said turntable spindle torotate'relatively to said first-named spindle.

10. The combination with a phonograph turntable adapted to rotaterecords of different reproducing speeds, of a motor for driving saidturntable, a shaft driven by said motor at a predetermined speed havinga driving member on the end thereof, a spindle connected with saidturntable having a driven member mounted thereon, said driven memberbeing adapted to embrace said driving member, a plurality of ballsmounted for rotation in said driven member adapted to be engaged androtated by said driving member, and means for clamping said balls innon-rotating position for locking with said driving member whereby saidturntable will be directly driven'thereby, and release said balls forpermitting rotating movementfthereof whereby said driven member will beindirectly driven therethrough for rotating said turntable at a slowerspeed. y

11. The combination with a phonograph turntable adapted to`rotaterecords of different reproducing speeds, of a motor for driving saidturntable, a. shaft driven by said motor at a predetermined speed havinga driving member on the end thereof, a spindle connected with saidturntable having a driven member mounted thereon, said driven memberbeing adapted to embrace said driving member, a plurality of ballsmounted for rotation in said driven member adapted to be engaged androtated by' said driving member, means for clamping said balls innon-rotating position for locking with said driving member whereby saidturntable will be directly driven thereby, and release said balls forpermitting rotating movement thereof whereby said driven member will beindirectly driven therethrough for rotating said turntable at a slowerspeed, and manually operated means for altering the driving function ofsaid balls as above set forth.

12. The combination with a phonograph turntable adapted to rotaterecords of different reproducing speeds, of a motor for driving saidlturntable, a shaft driven by said motor at a thereon, said drivenmember being adapted to embrace said driving member,y a plurality ofballs mounted for rotation in`said driven member adapted to be engagedand rotated by said driving member, and a ball race adapted to be lockedwith said balls and driven member for causing said driven member to bedirectly driven therethrough and unlocked therefrom to provide a ballrace for said balls for obtaining a slower speed.

13. The combination with a phonograph turntable adapted to rotaterecords of different reproducing speeds, of a motor. for driving saidturntable, a shaft driven by said motor at a predetermined speed havinga driving member on the end thereof, a spindle connected with saidturntable having a driven member mounted thereon, said driven memberbeing adapted to embrace said driving member, a plurality of ballsmounted for rotation in said driven member adapted to be engaged androtated by said driving member, a ball race adapted to be locked withtable adapted to rotate records of different reproducing speeds, of amotor for driving said turntable, a shaft driven by said motor at apredetermined speed having a driving member on the end thereof, aspindle connected with said turntable having 'a driven vmember mountedthereon, said driven member being adapted to embrace said drivingmember, a stationary support for said turntable and spindle, a pluralityof balls mounted for rotation in said driven member adapted to beengaged and rotated by said driving member, a ball race' adapted to belocked with said balls and driven member for causing said driven memberto be directly driven therethrough and unlocked therefrom to provide aball race for said balls for obtaining a slower speed, and a clutchmember for locking said race with said driving member while releasing itfrom the support when said clutch is in one position and when in theotherposition lockingthe same with said support while releasing it fromsaid driven member.

15. The combination with a phonograph turntable adapted to rotaterecords of different reproducing speeds, of a motor for driving saidturntable, a drive shaft driven by said motor at a predetermined speedof rotation, means for frictionally connecting said turntable with saiddrive shaft whereby said turntable will be directly driven at the samespeed of rotation, and means for releasing said frictional contact andapplying iii-piace thereof a diierential speed transmission forimparting to said turntable a decreased speed of rotation.

FREDERICK C. BARTON.

